Experimental and numerical investigation on rap mixtures at low temperature

In this paper, the low temperature behavior of asphalt mixture containing Reclaimed Asphalt Pavement (RAP) was experimentally and numerically investigated. For this purpose, four asphalt mixtures prepared with different percentages of RAP were tested with the Bending Beam Rheometer (BBR) to determine their creep stiffness, S(t). Then, the S(t) of the asphalt binder contained in the mixtures was back-calculated through the Shift-Homothety-Shift in time-Shift (SHStS) transformation. Finally, two-dimensional Finite Element Model (FEM) simulations of BBR tests were used to validate the back-calculation results based on Digital Image Processing (DIP) technique. It was found that experimentally measured and FEM predicted asphalt mixture creep stiffness are reasonably close, suggesting that both SHStS and FEM represents satisfactory modeling tools.